Toner

ABSTRACT

Provided is a toner, including a toner particle having: a toner base particle containing a binder resin and a colorant; and protrusion derived from a resin fine particle in a surface of the toner base particle, wherein the protrusion is covered with a condensation product of an organosilicon compound represented by the formula (1), and wherein the resin fine particle is in direct contact with the toner base particle.
 
(R a ) n —Si—(R b ) 4-n   (1)

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a toner for developing an electrostaticimage (electrostatic latent image) to be used in image forming methods,such as electrophotography and electrostatic printing.

Description of the Related Art

In recent years, along with the development of computers and multimedia,a unit for outputting a full-color image on demand has been desired in awide variety of fields ranging from an office to a house, and hence animprovement in performance of a copying machine or a printer has beenrequired. Requirements for on-demand printing include an increase incapacity of a toner cartridge and a reduction in amount of toner to beused. In each of the cases, the lengthening of the lifetime of the tonercartridge is needed.

The following condition is required for lengthening the lifetime of thetoner cartridge. The properties of the toner are not changed even bymulti-sheet printing. In a related-art toner, inorganic fine particlesare externally added to the surface of a toner base particle, and hencethe inorganic fine particles enter a space between a toner particle anda photosensitive member to reduce a contact area therebetween. However,when the inorganic fine particles are detached by the multi-sheetprinting, the toner base particle and the photosensitive member areliable to be brought into direct contact with each other. Accordingly,the contact area between the toner particle and the photosensitivemember increases to deteriorate the transferability of the toner in somecases. In order to prevent such deterioration of the transferability, aninvestigation has been conducted on the suppression of the detachment ofthe inorganic fine particles not only through the external addition ofthe inorganic fine particles to the toner base particle but also throughthe application of heat or mechanical impact.

However, when the detachment of the inorganic fine particles from thetoner base particle is suppressed, at the time of the application of aforce to the inorganic fine particles, the force is liable to betransmitted as it is to the photosensitive member. Accordingly, anexcessively large force is applied to the photosensitive member, andhence the surface layer of the photosensitive member is shaved at thetime of the multi-sheet printing in some cases. Accordingly, when theinorganic fine particles are used, it has been difficult to achieve bothan improvement in transferability of the toner and the prevention of theshaving of the photosensitive member at the time of the multi-sheetprinting.

It is conceivable from the foregoing that when organic fine particleshaving hardnesses lower than those of the inorganic fine particles arebrought into close contact with the surface layer of a toner base body,the shaving of the photosensitive member can be prevented. In, forexample, Japanese Patent Application Laid-Open No. 2012-194314, there isa disclosure of a toner having protrusions formed of resin fineparticles in the surface layer of a toner base body. In addition, inJapanese Patent Application Laid-Open No. 2015-106023, there is adisclosure of a toner in which after organic fine particles have beencaused to adhere to the surface layer of a toner base body, the organicfine particles are fixed with a shell layer containing a thermosettingresin.

However, the transferability of the toner described in Japanese PatentApplication Laid-Open No. 2012-194314 is low in some cases, though thestabilization of the chargeability of the toner and the heat-resistantstorage stability thereof can be achieved by the resin fine particles.This is probably because the resin fine particles forming theprotrusions have so low hardnesses as to be liable to deform, and hencea contact area between a toner particle and a photosensitive memberincreases. In addition, the toner fuses to a developing member in somecases. This is probably because the resin fine particles have so lowhardnesses as to be liable to collapse, and hence the toner is liable tomigrate to the developing member with the collapsed resin fine particlesas starting points.

In addition, in the toner described in Japanese Patent ApplicationLaid-Open No. 2015-106023, the detachment of the organic fine particlescan be prevented by the shell containing the thermosetting resin, but asin the toner described in Japanese Patent Application Laid-Open No.2012-194314, the transferability of the toner may be low or its fusionto a developing member may occur. A possible cause for the foregoing isas described below. The thermosetting resin is an organic shell layerand hence has a hardness lower than that of an inorganic shell layerformed of a silane coupling agent or the like. The resin fine particlesare covered with the organic shell layer having a low hardness, andhence the deformation and collapse of the resin fine particles cannot besufficiently prevented. As a result, the reduction in transferability orthe fusion to the developing member may occur.

The present invention has been made in view of the problems. That is, anobject of the present invention is to provide a toner that achieves bothhigh transferability and the prevention of member contamination at thetime of multi-sheet printing.

SUMMARY OF THE INVENTION

The present inventors have made extensive investigations, and as aresult, have found that the problems can be solved by the followingconstruction.

That is, the present invention relates to a toner, including a tonerparticle having: a toner base particle containing a binder resin and acolorant; and a protrusion derived from a resin fine particle in asurface of the toner base particle, wherein a surface of the protrusionis covered with a condensation product of an organosilicon compoundrepresented by the following formula (1), and wherein the resin fineparticle is in direct contact with the toner base particle:(R^(a))_(n)—Si—(R^(b))_(4-n)  (1)in the formula (1), R^(a) represents a halogen atom, a hydroxy group, oran alkoxy group, R^(b) represents an alkyl group, an alkenyl group, anacetoxy group, an acyl group, an aryl group, an acryloxyalkyl group, ora methacryloxyalkyl group, and n represents an integer of from 2 to 4,provided that when a plurality of R^(a)'s or R^(b)'s exist, theplurality of R^(a)'s or the plurality of R^(b)'s may be identical to ordifferent from each other.

Further features of the present invention will become apparent from thefollowing description of exemplary embodiments with reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an explanatory view of a height h of a protrusion and aclose-contact width A of the protrusion.

FIG. 2 is a view for illustrating an example of a silicon mapping imageof one particle of a toner according to the present invention taken witha transmission electron microscope (TEM).

DESCRIPTION OF THE EMBODIMENTS

Preferred embodiments of the present invention will now be described indetail in accordance with the accompanying drawings.

An embodiment for carrying out the present invention is described.

The present invention relates to a toner, including a toner particlehaving: a toner base particle containing a binder resin and a colorant;and a protrusion derived from a resin fine particle in a surface of thetoner base particle, wherein a surface of the protrusion is covered witha condensation product of an organosilicon compound represented by thefollowing formula (1), and wherein the resin fine particle is in directcontact with the toner base particle:(R^(a))_(n)—Si—(R^(b))_(4-n)  (1)in the formula (1), R^(a) represents a halogen atom, a hydroxy group, oran alkoxy group, R^(b) represents an alkyl group, an alkenyl group, anacetoxy group, an acyl group, an aryl group, an acryloxyalkyl group, ora methacryloxyalkyl group, and n represents an integer of from 2 to 4,provided that when a plurality of R^(a)'s or R^(b)'s exist, theplurality of R^(a)'s or the plurality of R^(b)'s may be identical to ordifferent from each other.

The outline of the present invention is described below.

The phrase “in direct contact” as used in the present invention meansthat the resin fine particles are in surface contact with the toner baseparticle. Here, when the height of a protrusion is represented by h andthe close-contact width of the protrusion is represented by A, the resinfine particles are preferably in contact with the toner base particle sothat the relationship of 0.20≤h/A≤1.50, more preferably the relationshipof 0.25≤h/A≤1.00 may be satisfied from the viewpoints of an improvementin transferability of the toner and the prevention of protrusiondetachment (FIG. 1). When the ratio h/A is 0.20 or more, a gap betweenthe toner particle and any other member enlarges, and hence thetransferability of the toner is improved. In addition, when the ratioh/A is 1.50 or less, the surfaces of the resin fine particles in closecontact with the toner base particle are sufficiently wide, and hencethe protrusion detachment hardly occurs even when a force is applied tothe protrusions. The ratio h/A can be calculated with a silicon mappingimage of the toner particle taken by a method to be described later.

In addition, the “protrusion derived from the resin fine particle” inthe present invention can be distinguished from a protrusion derivedfrom the toner base particle by using various analysis approaches aftera section of one particle of the toner has been exposed with, forexample, a microtome. Specific examples of the analysis approachesinclude an approach involving performing the distinction based on adifference in contrast shown in a backscattered electron image of ascanning electron microscope, and an approach involving performing thedistinction based on a difference in spectrum of electron energy lossspectroscopy (EELS).

In the present invention, the ratio at which the resin fine particlesare each in direct contact with the toner base particle is preferably ashigh as possible. Specifically, in the silicon mapping image of thetoner particle taken by the method to be described later, the ratio atwhich the toner base particle and each of the resin fine particles arein direct contact with each other at an interface therebetween withoutthrough the layer of the condensation product of the organosiliconcompound is preferably 20% or more when the length of the interface isdefined as 100%.

A related-art toner has involved the following problem: in the casewhere a stress is continuously applied to a toner at the time ofmulti-sheet printing, when the hardness of a protrusion is low,protrusion collapse occurs, and when the hardness of the protrusion ishigh, protrusion detachment occurs. The occurrence of the protrusioncollapse has been a cause for a reduction in transferability of thetoner because a contact area between a toner particle and aphotosensitive member increases, or has been a cause for the fusion ofthe toner particle to a developing member. The protrusion detachment hasbeen a cause for the reduction in transferability because the contactarea between the toner particle and the photosensitive member increases,or has been a cause for the fusion of a resin fine particle detachedfrom the toner particle to the developing member.

The present inventors have made extensive investigations, and have foundthat a toner that achieves both high transferability and the preventionof member contamination at the time of multi-sheet printing can beproduced by covering the surface of each of the resin fine particles indirect contact with the toner base particle with the condensationproduct of the organosilicon compound represented by the formula (1).The present inventors have considered a reason for the foregoing to beas described below.

The protrusions of the toner particle of the present invention eachsimultaneously have the following two different characteristics: a highhardness of the surface layer of the protrusion based on thecondensation product of the organosilicon compound; and a low hardnessof the inside of the protrusion based on the resin fine particle.Further, the resin fine particles are in direct contact with the tonerbase particle, and hence the resin fine particles and the toner baseparticle are integrated with each other. The present inventors haveconsidered that accordingly, protrusion collapse is prevented by thehigh hardness of the surface layer of the protrusion, and at the sametime, protrusion detachment is prevented by the low hardness of theinside of the protrusion because a force from the outside is absorbedand the force is released to the toner base particle with which theresin fine particles are integrated. The present inventors haveconsidered that as a result of the foregoing, the toner of the presentinvention prevents the fusion of the toner particle to a developingmember due to the protrusion collapse or the fusion of a resin fineparticle thereto due to the protrusion detachment even at the time ofthe multi-sheet printing.

In addition, the protrusions of the toner of the present invention incontact with a photosensitive member are considered to be substantiallyfree from deforming in a transfer step because the protrusions are eachcovered with the condensation product of the organosilicon compound. Thepresent inventors have considered that accordingly, the toner particleand the photosensitive member are brought into point contact with eachother by the protrusions that have entered a space between the tonerbase particle and the photosensitive member, and hence the hightransferability of the toner can be achieved. In view of the foregoing,the present inventors have considered that the toner that achieves boththe high transferability and the prevention of member contamination atthe time of the multi-sheet printing can be produced by covering thesurface of each of the protrusions derived from the resin fine particleswith the condensation product of the organosilicon compound.

Details about the organosilicon compound and the resin fine particles tobe used in the present invention are described below.

(Organosilicon Compound)

The content of the condensation product of the organosilicon compound inthe resin fine particles is preferably 0.1 part by mass or more and 20.0parts by mass or less with respect to 100.0 parts by mass of the tonerbase particle. In addition, the content is more preferably 0.3 part bymass or more and 15.0 parts by mass or less, still more preferably 0.5part by mass or more and 10.0 parts by mass or less. When the content ofthe condensation product of the organosilicon compound is 0.1 part bymass or more, the condensation product of the organosilicon compoundmoderately covers the surface layer of each of the protrusions derivedfrom the resin fine particles, and hence the deformation of theprotrusions hardly occurs in the transfer step. In addition, when thecontent of the condensation product of the organosilicon compound is20.0 parts by mass or less, the protrusions moderately deform at thetime of a development step to absorb a force. Accordingly, the force tobe transmitted to a photosensitive member reduces and hence the shavingof the photosensitive member is suppressed.

The surface of each of the protrusions derived from the resin fineparticles is covered with the condensation product of the organosiliconcompound represented by the formula (1). Two or more kinds oforganosilicon compounds may be used as the organosilicon compound toform a condensation product as long as the compounds are eachrepresented by the formula (1).

Examples of the compound represented by the formula (1) serving as theorganosilicon compound include difunctional, trifunctional, andtetrafunctional organosilicon compounds. Of those, a difunctional ortrifunctional organosilicon compound (n in the formula (1) represents 2or 3) is particularly preferably used because the protrusions moderatelydeform in the development step to suppress the shaving of thephotosensitive member.

Examples of the difunctional organosilicon compound includedimethyldimethoxysilane and dimethyldiethoxysilane.

Examples of the trifunctional organosilicon compound include:trifunctional alkyl group-containing silane compounds, such asmethyltrimethoxysilane, methyltriethoxysilane,methyldiethoxymethoxysilane, methylethoxydimethoxysilane,ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane,propyltriethoxysilane, butyltrimethoxysilane, butyltriethoxysilane,hexyltrimethoxysilane, hexyltriethoxysilane, octyltrimethoxysilane,octyltriethoxysilane, octadecyltrimethoxysilane, andoctadecyltriethoxysilane; trifunctional alkenyl group-containing silanecompounds, such as vinyltrimethoxysilane, vinyltriethoxysilane,allyltrimethoxysilane, and allyltriethoxysilane; trifunctional arylgroup-containing silane compounds, such as phenyltrimethoxysilane andphenyltriethoxysilane; trifunctional acryloxyalkyl group-containingsilane compounds, such as γ-acryloxypropyltrimethoxysilane,γ-acryloxypropyltriethoxysilane, γ-acryloxypropyldiethoxymethoxysilane,and γ-acryloxypropylethoxydimethoxysilane; and trifunctionalmethacryloxyalkyl group-containing silane compounds, such asγ-methacryloxypropyltrimethoxysilane,γ-methacryloxypropyltriethoxysilane,γ-methacryloxypropyldiethoxymethoxysilane, andγ-methacryloxypropylethoxydimethoxysilane.

Examples of the tetrafunctional organosilicon compound includetetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, andtetrabutoxysilane.

In addition, in the present invention, two or more kinds oforganosilicon compounds may be used in combination. The combined use ofthe organosilicon compounds can impart different functions based on therespective organosilicon compounds to the toner particle. Theorganosilicon compounds to be used in combination may each be anorganosilicon compound represented by the formula (1), or may each be anorganosilicon compound except the foregoing. Examples of theorganosilicon compound except the organosilicon compound represented bythe formula (1) include various monofunctional organosilicon compounds.Examples of the monofunctional organosilicon compounds includetrimethylethoxysilane, triethylmethoxysilane, triethylethoxysilane,triisobutylmethoxysilane, triisopropylmethoxysilane, andtri(2-ethylhexyl)methoxysilane.

(Resin Fine Particles)

The number-average particle diameter of the resin fine particles ispreferably 10 nm or more and 500 nm or less, more preferably 15 nm ormore and 300 nm or less. When the number-average particle diameter ofthe resin fine particles is 10 nm or more, a gap is formed between amember, such as a photosensitive drum or an intermediate transfer belt,and the toner particle, and hence the member is hardly brought intodirect contact with the toner base particle. Thus, a contact areabetween the toner particle and the member reduces, and hence thetransferability of the toner is improved. In addition, when thenumber-average particle diameter of the resin fine particles is 500 nmor less, the protrusions derived from the resin fine particles are notexcessively high, and hence protrusion detachment is alleviated.

In addition, the kinds of the resin fine particles in the presentinvention are not particularly limited, but the resin fine particles arepreferably thermoplastic fine particles. When the thermoplastic fineparticles are used, the protrusions derived from the resin fineparticles are more hardly detached from the toner base particle. This isprobably because the resin fine particles that are thermoplastic areeasily integrated with the toner base particle that is alsothermoplastic. Further, the use of the thermoplastic fine particlesimproves the fixability of the toner. This is probably because athermoplastic resin forming the resin fine particles easily melts at thetime of the fixation of the toner.

Examples of the thermoplastic fine particles include a vinyl-basedresin, a polyester resin, a polyamide resin, and a fluorine resin. Asthe vinyl-based resin, there may be used, for example, a polymer or acopolymer of a monomer such as ethylene, propylene, isobutylene,styrene, or α-methylstyrene; an unsaturated carboxylic acid ester, suchas methyl acrylate, butyl acrylate, methyl methacrylate, 2-hydroxyethylmethacrylate, t-butyl methacrylate, or 2-ethylhexyl methacrylate; anunsaturated carboxylic acid, such as acrylic acid or methacrylic acid;an unsaturated dicarboxylic acid, such as maleic acid; an unsaturateddicarboxylic acid anhydride, such as maleic anhydride; a nitrile-basedvinyl monomer, such as acrylonitrile; a halogen-containing vinylmonomer, such as vinyl chloride; or a nitro-based vinyl monomer, such asnitrostyrene.

In addition, the glass transition temperature (Tg) of the resin fineparticles in the present invention is preferably 40° C. or more and 110°C. or less, more preferably 50° C. or more and 100° C. or less, stillmore preferably 60° C. or more and 95° C. or less. When the Tg of theresin fine particles is 40° C. or more, the protrusions derived from theresin fine particles hardly collapse, and hence the fusion of the resinforming the resin fine particles to a member hardly occurs. In addition,when the Tg of the resin fine particles is 110° C. or less, the tonerbase particle and the resin fine particles are more easily integratedwith each other, and hence the protrusions derived from the resin fineparticles are hardly detached from the toner base particle. Further,when the Tg of the resin fine particles is 110° C. or less, the resinfine particles easily deform at the time of the application of heat in afixation step, and hence the fixation temperature of the toner can bereduced.

Further, the peak top molecular weight Mp of the resin fine particles inthe present invention is preferably 3,000 or more and 50,000 or less.When the Mp of the resin fine particles is 3,000 or more, theprotrusions derived from the resin fine particles hardly collapse, andhence the fusion of the resin to a member hardly occurs. In addition,when the Mp of the resin fine particles is 50,000 or less, the tonerbase particle and the resin fine particles are more easily integratedwith each other, and hence the protrusions derived from the resin fineparticles are hardly detached from the toner base particle.

Further, the resin fine particles in the present invention eachpreferably contain a resin having an ionic functional group. The use ofthe resin fine particles each containing the resin having an ionicfunctional group in the toner particle according to the presentinvention improves the charge rising performance of the toner. Thepresent inventors have considered a reason for the foregoing to be asdescribed below.

A toner having satisfactory charge rising performance means such a tonerthat when the toner and a charging member are brought into contact witheach other, the charge quantity of the toner is saturated within a shorttime period. In order to saturate the charge quantity within a shorttime period, charge needs to easily transfer from the protrusions of thesurface layer of the toner particle in contact with the charging memberto the entirety of the surface layer of the same toner particle. In thepresent invention, the protrusions of the surface layer of the tonerparticle in contact with the charging member and the toner base particleare each covered with the condensate of the organosilicon compound.Accordingly, a contact area between the protrusions and the toner baseparticle increases, and hence the charge easily transfers. Further, theuse of the resin having an ionic functional group facilitates thetransfer of the charge also on the surface layers of the resin fineparticles, and hence enables the charge to rapidly transfer to theentirety of the surface layer of the same toner particle. The presentinventors have considered that the charge rising performance is improvedbecause of the foregoing.

Examples of the ionic functional group include a sulfo group, an aminogroup, a carboxy group, and a phenolic hydroxy group. Examples of theresin containing an ionic functional group include: resins such as apolyester resin, a melamine resin, a guanamine resin, a urea resin, andan aniline resin; and resins each obtained by polymerization orcopolymerization of a monomer such as acrylic acid, methacrylic acid,vinylsalicylic acid, phthalic acid 1-vinyl ester, vinylbenzoic acid,1-vinylnaphthalene-2-carboxylic acid,2-acrylamido-2-methylpropanesulfonic acid, sodium p-styrenesulfonate,potassium p-styrenesulfonate, lithium p-styrenesulfonate, or ap-styrenesulfonic acid ester, such as a p-styrenesulfonic acid ethylester.

The content of the resin fine particles with respect to the toner baseparticle is preferably 0.1 part by mass or more and 15.0 parts by massor less with respect to 100.0 parts by mass of the toner base particlefrom the viewpoint of the transferability of the toner. The content ismore preferably 0.3 part by mass or more and 10.0 parts by mass or less,still more preferably 0.5 part by mass or more and 7.0 parts by mass orless. When the content of the resin fine particles is 0.1 part by massor more, a member, such as a photosensitive drum or an intermediatetransfer belt, is hardly brought into direct contact with the toner baseparticle. Accordingly, a contact area therebetween reduces and hence thetransferability is improved. In addition, when the content of the resinfine particles is 15.0 parts by mass or less, the number of the resinfine particles in contact with the member is suppressed. Accordingly, acontact area between the member and the resin fine particles reduces,and hence the transferability is improved.

Next, a method of producing the toner particle according to the presentinvention is described. However, the present invention is not limitedthereto.

The toner particle according to the present invention is preferablyproduced by a method involving: first producing the resin fine particlesand the toner base particle separately from each other; bringing theproduced resin fine particles into close contact with the toner baseparticle; and then covering the toner base particle with thecondensation product of the organosilicon compound. Details about amethod of producing the toner particle according to the presentinvention based on the method are described below.

(Method of Producing Resin Fine Particles)

Any method may be used as a method of producing resin fine particles.For example, known methods, such as an emulsion polymerization method, asoap-free emulsion polymerization method, a phase inversionemulsification method, and a mechanical emulsification method, can beused. Of those production methods, a phase inversion emulsificationmethod is preferred because an emulsifier and a dispersion stabilizerare not required, and resin fine particles each having a smallerparticle diameter can be obtained easily.

In the phase inversion emulsification method, when the resin isdissolved in an organic solvent, and a neutralizing agent is added tothe solution, followed by mixing with an aqueous medium with stirring,the solution of the resin is subjected to phase inversion emulsificationto generate resin fine particles. The organic solvent is removed by amethod such as heating or reduction in pressure after the phaseinversion emulsification. Thus, according to the phase inversionemulsification method, a stable aqueous dispersion of resin fineparticles can be obtained substantially without using an emulsifier or adispersion stabilizer.

In the phase inversion emulsification method, a resin havingself-dispersibility or a resin that can express self-dispersibilitythrough neutralization is used. Here, the self-dispersibility of theresin in the aqueous medium is exhibited in a resin having a hydrophilicgroup in a molecule thereof. Specifically, a resin having a polyethergroup or an ionic functional group is preferred.

(Method of Producing Toner Base Particle)

A method of producing the toner base particle is not particularlylimited, and is, for example, a suspension polymerization method, adissolution suspension method, an emulsion aggregation method, or apulverization method. When the toner base particle is produced in theaqueous medium, the toner base particle may be used as it is in the nextstep (a step of bringing the resin fine particles into close contactwith the toner base particle), or the toner base particle may beredispersed in the aqueous medium after having been washed, filtered,and dried. When the toner base particle is produced by a dry process,the toner base particle may be dispersed in the aqueous medium by aknown method. In order to disperse the toner base particle in theaqueous medium, the aqueous medium preferably contains a dispersionstabilizer.

When the toner base particle is obtained, a polymerizable monomercomposition is prepared by: adding a polymerizable monomer and variousmaterials (e.g., a colorant, a wax, a charge control agent, and a polarresin); and melting, dissolving, or dispersing the materials with adispersing machine. At this time, a wax, a charge control agent, asolvent for viscosity adjustment, a crystalline resin, a chain transferagent, or any other additive can be appropriately added to thepolymerizable monomer composition as required. Examples of thedispersing machine include a homogenizer, a ball mill, a colloid mill,and an ultrasonic dispersing machine.

Next, the polymerizable monomer composition is loaded into an aqueousmedium containing poorly water-soluble inorganic fine particles preparedin advance, and a suspension is prepared by dispersing the mixture witha high-speed dispersing machine, such as a high-speed stirring machineor an ultrasonic dispersing machine (granulation step). Examples of thepoorly water-soluble inorganic fine particles include: hydroxyapatite;phosphates, such as tribasic calcium phosphate, dibasic calciumphosphate, magnesium phosphate, aluminum phosphate, and zinc phosphate;carbonates, such as calcium carbonate and magnesium carbonate; metalhydroxides, such as calcium hydroxide, magnesium hydroxide, and aluminumhydroxide; sulfates, such as calcium sulfate and barium sulfate; calciummetasilicate; bentonite; silica; and alumina.

After that, the polymerizable monomer in the suspension is polymerizedto produce the binder resin (polymerization step).

A polymerization initiator may be mixed together with any other additiveat the time of the preparation of the polymerizable monomer composition,or may be mixed into the polymerizable monomer composition immediatelybefore being suspended in the aqueous medium. In addition, during thegranulation or after the completion of the granulation, that is,immediately before the initiation of the polymerization reaction, theinitiator can be added in a state of being dissolved in thepolymerizable monomer or any other solvent as required. After thepolymerizable monomer has been polymerized to produce the binder resin,desolvation treatment is performed as required. Thus, an aqueousdispersion liquid of the toner base particle is formed.

In addition, the glass transition temperature (Tg) of the toner baseparticle is preferably 40° C. or more and 75° C. or less, morepreferably 40° C. or more and 65° C. or less. In addition, the peak topmolecular weight (Mp) of the toner base particle in a molecular weightdistribution measured by gel permeation chromatography (GPC) ispreferably 5,000 or more and 50,000 or less.

(Method of Bringing Resin Fine Particles into Close Contact with TonerBaser Particle)

In the present invention, a method of bringing the resin fine particlesinto direct contact with the toner base particle is not particularlylimited. The resin fine particles may be added to a toner baseparticle-dispersed liquid and then buried in the toner base particlewith mechanical force of impact, or the resin fine particles may bebrought into close contact with the toner base particle by heating theaqueous medium. Alternatively, the resin fine particles may be broughtinto close contact with the toner base particle by adding an aggregatingagent, or the above-mentioned procedures may be combined. In any case,it is preferred that the aqueous medium having dispersed therein theresin fine particles and the toner base particles be stirred.

From the viewpoint of increasing the contact area between the resin fineparticles and the toner base particle, a procedure for heating theaqueous medium to at least a glass transition temperature of the tonerbase particle is more preferred. Through setting of the aqueous mediumto the above-mentioned temperature, the toner base particle is softened,and hence the resin fine particles are easily brought into close contactwith the toner base particle.

The resin fine particles and the toner base particle are preferablybrought into close contact with each other by adjusting, under a statein which the resin fine particles and the toner base particle are causedto coexist in the aqueous medium, the pH of the aqueous medium to such apH that the resin fine particles are easily dispersed in the aqueousmedium, followed by heating. According to the method, the resin fineparticles can be brought into direct contact with the toner baseparticle in a state of being dispersed, and the aggregation of the tonerbase particles hardly occurs.

(Method of Covering Toner Base Particle)

A method of covering the toner base particle in close contact with theprotrusions derived from the resin fine particles with the condensate ofthe organosilicon compound is described below. However, the coveringmethod is not limited thereto.

A preferred production method for the condensate is a method involving:preparing a mixed solution containing, in the aqueous medium, theorganosilicon compound represented by the formula (1) or a hydrolysatethereof, and the toner base particle in close contact with theprotrusions derived from the resin fine particles; and then condensingthe organosilicon compound.

The organosilicon compound may be added to and mixed in the aqueousmedium by any method. For example, the organosilicon compound may beadded as it is. In addition, the organosilicon compound may be addedafter having been mixed with the aqueous medium to be hydrolyzed.

In addition, a reaction of the organosilicon compound is known to havepH dependence, and hence the pH of the aqueous medium is preferablyadjusted to 7.0 or more and 12.0 or less during the progress of thecondensation.

The pH of the aqueous medium or the mixed solution only needs to beadjusted with an existing acid or base. Examples of the acid foradjusting the pH include: hydrochloric acid, bromic acid, iodic acid,perchloric acid, perbromic acid, metaperiodic acid, permanganic acid,thiocyanic acid, sulfuric acid, nitric acid, phosphonic acid, phosphoricacid, diphosphoric acid, hexafluorophosphoric acid, tetrafluoroboricacid, tripolyphosphoric acid, aspartic acid, o-aminobenzoic acid,p-aminobenzoic acid, isonicotinic acid, oxaloacetic acid, citric acid,2-glycerophosphoric acid, glutamic acid, cyanoacetic acid, oxalic acid,trichloroacetic acid, o-nitrobenzoic acid, nitroacetic acid, picricacid, picolinic acid, pyruvic acid, fumaric acid, fluoroacetic acid,bromoacetic acid, o-bromobenzoic acid, maleic acid, and malonic acid.

Examples of the base for adjusting the pH include: hydroxides of alkalimetals, such as potassium hydroxide, sodium hydroxide, and lithiumhydroxide, and aqueous solutions thereof, carbonates of alkali metals,such as potassium carbonate, sodium carbonate, and lithium carbonate,and aqueous solutions thereof, sulfates of alkali metals, such aspotassium sulfate, sodium sulfate, and lithium sulfate, and aqueoussolutions thereof; phosphates of alkali metals, such as potassiumphosphate, sodium phosphate, and lithium phosphate, and aqueoussolutions thereof, hydroxides of alkaline earth metals, such as calciumhydroxide and magnesium hydroxide, and aqueous solutions thereof,ammonia; basic amino acids, such as histidine, arginine, and lysine, andaqueous solutions thereof; and trishydroxymethylaminomethane.

Preferred examples of the aqueous medium in the present inventioninclude water, alcohols, such as methanol, ethanol, and propanol, andmixed solvents thereof.

The colorant, the binder resin, the wax, and the charge control agent tobe incorporated into the toner base particle/the toner particle, andinorganic fine particles to be externally added are described below.

(Colorant)

Conventionally known pigments and dyes corresponding to the respectiveblack, yellow, magenta, and cyan colors, and other colors, magneticmaterials, and the like can each be used as the colorant to beincorporated into the toner base particle without any particularlimitation.

Examples of the yellow pigment include: a monoazo compound; a disazocompound; a condensed azo compound; an isoindolinone compound; anisoindoline compound; a benzimidazolone compound; an anthraquinonecompound; an azo metal complex; a methine compound; and an arylamidecompound. A specific example thereof is C.I. Pigment Yellow 74, 93, 95,109, 111, 128, 155, 174, 180, or 185.

Examples of the magenta pigment include: a monoazo compound; a condensedazo compound; a diketopyrrolopyrrole compound; an anthraquinonecompound; a quinacridone compound; a basic dye lake compound; a naphtholcompound; a benzimidazolone compound; a thioindigo compound; and aperylene compound. Specific examples thereof include: C.I. Pigment Red2, 3, 5, 6, 7, 23, 48:2, 48:3, 48:4, 57:1, 81:1, 122, 144, 146, 150,166, 169, 177, 184, 185, 202, 206, 220, 221, 238, 254, or 269; and C.I.Pigment Violet 19.

Examples of the cyan pigment include: a copper phthalocyanine compoundand a derivative thereof; an anthraquinone compound; and a basic dyelake compound. A specific example thereof is C.I. Pigment Blue 1, 7, 15,15:1, 15:2, 15:3, 15:4, 60, 62, or 66.

Examples of the black pigment include carbon black, aniline black,non-magnetic ferrite, and magnetite. In addition, a pigment toned to ablack color with the yellow pigment, the magenta pigment, and the cyanpigment may be used.

Further, a magnetic material can be incorporated into the toner baseparticle of the present invention to turn the toner base particle into amagnetic toner base particle. In this case, the magnetic material canalso serve as a colorant. Examples of the magnetic material include: aniron oxide typified by magnetite, hematite, or ferrite; a metal typifiedby iron, cobalt, or nickel, or an alloy formed of any such metal and ametal such as aluminum, cobalt, copper, lead, magnesium, tin, zinc,antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium,titanium, tungsten, or vanadium; and mixtures thereof.

Those pigments may be used alone or as a mixture, and may each be usedin the state of a solid solution. In addition, various dyesconventionally known as colorants may be used in combination with thepigments.

The content of the pigment is preferably 1.0 part by mass or more and20.0 parts by mass or less with respect to 100.0 parts by mass of thebinder resin.

(Binder Resin)

The toner base particle contains the binder resin. Examples of thebinder resin to be used in the present invention include a vinyl-basedresin, a polyester resin, a polyamide resin, a furan resin, an epoxyresin, a xylene resin, and a silicone resin. Of those, a vinyl-basedresin is preferably used. A polymer or a copolymer of such a monomer asdescribed below can be used as the vinyl-based resin: a styrene-basedmonomer, such as styrene or α-methylstyrene; an unsaturated carboxylate,such as methyl acrylate, butyl acrylate, methyl methacrylate,2-hydroxyethyl methacrylate, t-butyl methacrylate, or 2-ethylhexylmethacrylate; an unsaturated carboxylic acid, such as acrylic acid ormethacrylic acid; an unsaturated dicarboxylic acid, such as maleic acid;an unsaturated dicarboxylic acid anhydride, such as maleic anhydride; anitrile-based vinyl monomer, such as acrylonitrile; a halogen-containingvinyl monomer, such as vinyl chloride; or a nitro-based vinyl monomer,such as nitrostyrene. Of those, a copolymer of a styrene-based monomerand an unsaturated carboxylate is preferably used.

(Wax)

The toner base particle may contain the wax. Examples of the wax to beused in the present invention include:

an ester of a monohydric alcohol and an aliphatic monocarboxylic acid,or an ester of a monovalent carboxylic acid and an aliphaticmonoalcohol, such as behenyl behenate, stearyl stearate, or palmitylpalmitate; an ester of a dihydric alcohol and an aliphaticmonocarboxylic acid, or an ester of a divalent carboxylic acid and analiphatic monoalcohol, such as dibehenyl sebacate or hexanedioldibehenate; an ester of a trihydric alcohol and an aliphaticmonocarboxylic acid, or an ester of a trivalent carboxylic acid and analiphatic monoalcohol, such as glycerin tribehenate; an ester of atetrahydric alcohol and an aliphatic monocarboxylic acid, or an ester ofa tetravalent carboxylic acid and an aliphatic monoalcohol, such aspentaerythritol tetrastearate or pentaerythritol tetrapalmitate; anester of a hexahydric alcohol and an aliphatic monocarboxylic acid, oran ester of a hexavalent carboxylic acid and an aliphatic monoalcohol,such as dipentaerythritol hexastearate or dipentaerythritolhexapalmitate; an ester of a polyhydric alcohol and an aliphaticmonocarboxylic acid, or an ester of a polyvalent carboxylic acid and analiphatic monoalcohol, such as polyglycerin behenate; a natural esterwax, such as a carnauba wax or a rice bran wax; a petroleum-based wax ora derivative thereof, such as a paraffin wax, a microcrystalline wax, orpetrolatum; a hydrocarbon wax or a derivative thereof produced by aFischer-Tropsch method; a polyolefin wax or a derivative thereof, suchas a polyethylene wax or a polypropylene wax; a higher aliphaticalcohol; a fatty acid, such as stearic acid or palmitic acid; and anacid amide wax.

(Charge Control Agent)

The toner base particle may further contain the charge control agent. Aconventionally known charge control agent can be used as the chargecontrol agent without any particular limitation. Specific examplesthereof include negative charge control agents including: a metalcomplex of an aromatic carboxylic acid typified by salicylic acid, analkyl salicylic acid, a dialkyl salicylic acid, naphthoic acid, and adicarboxylic acid; a polymer or a copolymer having a sulfonic acidgroup, a sulfonic acid salt group, or a sulfonic acid ester group; ametal salt or a metal complex of an azo dye or an azo pigment; a boroncompound; a silicon compound; and calixarene. The examples also includepositive charge control agents including a quaternary ammonium salt, apolymer-type compound having a quaternary ammonium salt in a side chain,a guanidine compound, a nigrosine-based compound, and an imidazolecompound. As the polymer or copolymer having a sulfonic acid group, asulfonic acid salt group, or a sulfonic acid ester group, there may beused, for example: a homopolymer of a sulfonic acid group-containingvinyl-based monomer typified by styrenesulfonic acid,2-acrylamido-2-methylpropanesulfonic acid,2-methacrylamido-2-methylpropanesulfonic acid, vinylsulfonic acid,acrylsulfonic acid, or methacrylsulfonic acid; or a copolymer of thevinyl-based monomer shown in the “Binder Resin” section and the sulfonicacid group-containing vinyl-based monomer.

The addition amount of the charge control agent is preferably 0.01 partby mass or more and 20.0 parts by mass or less with respect to 100.0parts by mass of the binder resin.

(Inorganic Fine Particles)

The toner of the present invention may be used as a toner in the form ofa toner particle in which the toner base particle and the resin fineparticles in direct contact with its surface are each covered with thecondensation product of the organosilicon compound, or a productobtained by externally adding various inorganic fine particles to thetoner particle as required may be used as the toner. For example, thefollowing materials are used as the inorganic fine particles:

silica, titanium oxide, carbon black, and carbon fluoride, metal oxides(e.g., strontium titanate, cerium oxide, alumina, magnesium oxide, andchromium oxide), nitrides (e.g., silicon nitride), metal salts (e.g.,calcium sulfate, barium sulfate, and calcium carbonate), and fatty acidmetal salts (e.g., zinc stearate and calcium stearate).

The inorganic particles may also be subjected to hydrophobic treatmentin order to improve the flowability of the toner and to uniformize thecharging of the toner particles. As a treatment agent for hydrophobictreatment of the inorganic particles, there are given an unmodifiedsilicone varnish, various modified silicone varnishes, an unmodifiedsilicone oil, various modified silicone oils, a silane compound, asilane coupling agent, any other organosilicon compound, and anorganotitanium compound. Those treatment agents may be used alone or incombination thereof.

Measurement methods for physical property values specified in thepresent invention are described below.

<Particle Diameter of Toner Base Particle>

The number-average particle diameter (D1) and the weight-averageparticle diameter (D4) of the toner base particles are calculated asdescribed below. A precision particle size distribution measuringapparatus based on a pore electrical resistance method provided with a100 μm aperture tube “Coulter Counter Multisizer 3” (manufactured byBeckman Coulter, Inc.) is used as a measuring apparatus. Dedicatedsoftware included therewith “Beckman Coulter Multisizer 3 Version 3.51”(manufactured by Beckman Coulter, Inc.) is used for setting measurementconditions and analyzing measurement data. The measurement is performedwith the number of effective measurement channels of 25,000.

An electrolyte aqueous solution prepared by dissolving reagent gradesodium chloride in ion-exchanged water so as to have a concentration of1%, for example, “ISOTON II” (manufactured by Beckman Coulter, Inc.) canbe used in the measurement.

The dedicated software is set as described below prior to themeasurement and the analysis.

In the “Change Standard Operating Method (SOMME)” screen of thededicated software, the total count number of a control mode is set to50,000 particles, the number of times of measurement is set to 1, and avalue obtained by using “standard particles each having a particlediameter of 10.0 μm” (manufactured by Beckman Coulter, Inc.) is set as aKd value. A threshold and a noise level are automatically set bypressing a “Threshold/Measure Noise Level button”. In addition, acurrent is set to 1,600 μA, a gain is set to 2, and an electrolytesolution is set to ISOTON II, and a check mark is placed in a check box“Flush Aperture Tube after Each Run.”

In the “Convert Pulses to Size Settings” screen of the dedicatedsoftware, a bin spacing is set to a logarithmic particle diameter, thenumber of particle diameter bins is set to 256, and a particle diameterrange is set to the range of from 2 μm to 60 μm.

A specific measurement method is as described below.

(1) 200 mL of the electrolyte aqueous solution is charged into a250-milliliter round-bottom beaker made of glass dedicated forMultisizer 3. The beaker is set in a sample stand, and the electrolyteaqueous solution in the beaker is stirred with a stirrer rod at 24rotations/sec in a counterclockwise direction. Then, dirt and bubbles inthe aperture tube are removed by the “Flush Aperture” function of thededicated software.

(2) 30 mL of the electrolyte aqueous solution is charged into a100-milliliter flat-bottom beaker made of glass. 0.3 mL of a dilutedsolution obtained by diluting “Contaminon N” (10% aqueous solution of aneutral detergent for washing a precision measuring unit formed of anonionic surfactant, an anionic surfactant, and an organic builder, andhaving a pH of 7, manufactured by Wako Pure Chemical Industries, Ltd.)with ion-exchanged water by three fold in terms of a mass ratio is addedas a dispersant to the electrolyte aqueous solution.

(3) An ultrasonic dispersing unit “Ultrasonic Dispension System Tetra150” (manufactured by Nikkaki Bios Co., Ltd.) in which two oscillatorseach having an oscillatory frequency of 50 kHz are built so as to be outof phase by 180°, and which has an electrical output of 120 W isprepared. 3.3 L of ion-exchanged water is charged into the water tank ofthe ultrasonic dispersing unit. 2 mL of the Contaminon N is charged intothe water tank.

(4) The beaker in the section (2) is set in the beaker fixing hole ofthe ultrasonic dispersing unit, and the ultrasonic dispersing unit isoperated. Then, the height position of the beaker is adjusted in orderthat the liquid level of the electrolyte aqueous solution in the beakermay resonate with an ultrasonic wave from the ultrasonic dispersing unitto the fullest extent possible.

(5) 10 mg of the toner base particles are gradually added to anddispersed in the electrolyte aqueous solution in the beaker in thesection (4) under a state in which the electrolyte aqueous solution isirradiated with the ultrasonic wave. Then, the ultrasonic dispersiontreatment is continued for an additional 60 seconds. The temperature ofwater in the water tank is appropriately adjusted so as to be 10° C. ormore and 40° C. or less in the ultrasonic dispersion.

(6) The electrolyte aqueous solution in the section (5) in which thetoner base particles have been dispersed is dropped with a pipette tothe round-bottom beaker in the section (1) placed in the sample stand,and the concentration of the toner base particles to be measured isadjusted to 5%. Then, measurement is performed until the particlediameters of 50,000 particles are measured.

(7) The measurement data is analyzed with the dedicated softwareincluded with the apparatus, and the number-average particle diameter(D1) and the weight-average particle diameter (D4) are calculated.

<Particle Diameter of Resin Fine Particles>

The number-average particle diameter of the resin fine particles iscalculated by measuring a particle diameter by dynamic light scattering(DLS) through use of Zetasizer Nano-ZS (manufactured by MalvernInstruments Ltd.).

First, a power source of an apparatus is turned on and kept in thisstate for 30 minutes until a laser becomes stable. Then, Zetasizersoftware is activated. Manual is selected from a Measure menu, and thedetail of the measurement is input as described below.

Measurement mode: particle diameter

Material: Polystyrene latex (RI: 1.59, Absorption: 0.01)

Dispersant: Water (Temperature: 25° C., Viscosity: 0.8872 cP, RI: 1.330)

Temperature: 25.0° C.

Cell: Clear disposable zeta cell

Measurement duration: Automatic

A sample is prepared by diluting the resin fine particles with water sothat the sample may have a concentration of 0.50 mass %, and is filledinto a disposable cell. The cell is loaded into a cell holder of theapparatus.

When the above-mentioned preparation is finished, a Start button on ameasurement display screen is pressed to perform measurement.

The number-average particle diameter is calculated based on data on aparticle size distribution on a number basis, which is obtained byconverting a light intensity distribution obtained from DLS measurementby the Mie theory.

<Glass Transition Temperature (Tg) of Resin Fine Particles>

The glass transition temperature (Tg) of the resin fine particles ismeasured with a differential scanning calorimeter “Q2000” (manufacturedby TA Instruments) in conformity with ASTM D3418-82. The melting pointsof indium and zinc are used in the temperature correction of thedetecting portion of the apparatus, and the heat of fusion of indium isused in the correction of a heat quantity. Specifically, 3 mg of theresin fine particles are precisely weighed and loaded into an aluminumpan. An empty aluminum pan is used as a reference. The measurement isperformed in the measurement temperature range of from 30° C. to 200° C.at a preset rate of temperature increase of 10° C./min. A change inspecific heat of the resin fine particles is obtained in the temperatureincrease process. The glass transition temperature (Tg) of the resinfine particles is defined as the temperature of the point at which astraight line equidistant in a vertical axis direction from straightlines obtained by extending respective baselines before and after theobtainment of the change in specific heat of a reversible specific heatchange curve, and the curve of a portion where the glass transitiontemperature changes in a stepwise manner intersect each other.

<Peak Top Molecular Weight (Mp) of Resin Fine Particles>

The peak top molecular weight (Mp) of the resin fine particles ismeasured by gel permeation chromatography (GPC) as described below.

First, the resin fine particles are dissolved in tetrahydrofuran at roomtemperature over 24 hours. Then, the resultant solution is filtered witha solvent-resistant membrane filter “MYSYORI DISC” (manufactured byTosoh Corporation) having a pore diameter of 0.2 μm to provide a samplesolution. The sample solution is adjusted so that the concentration ofcomponents soluble in tetrahydrofuran may be 0.5 mass %. The measurementis performed by using the sample solution under the followingconditions.

Apparatus: HLC-8120 GPC (detector: RI) (manufactured by TosohCorporation)

Column: seven columns Shodex KF-801, 802, 803, 804, 805, 806, and 807(manufactured by Showa Denko K.K.) connected in series

Eluent: tetrahydrofuran

Flow rate: 1.0 mL/min

Oven temperature: 40.0° C.

Sample injection amount: 0.10 mL

At the time of the calculation of the molecular weight of the sample, amolecular weight calibration curve produced by using a standardpolystyrene resin (e.g., a resin available under the product name “TSKSTANDARD POLYSTYRENE F-850, F-450, F-288, F-128, F-80, F-40, F-20, F-10,F-4, F-2, F-1, A-5000, A-2500, A-1000, or A-500” from Tosoh Corporation)is used.

<Observation of Surface of Toner Particle>

The surface of the toner particle is observed as described below. Liquidnitrogen is poured into an anti-contamination trap attached to thehousing of a scanning electron microscope (SEM, apparatus name: S-4800,manufactured by Hitachi, Ltd.) until the liquid overflows, and the trapis left for 30 minutes. The “PC-SEM” of the S-4800 is activated toperform flushing (the cleaning of a FE chip serving as an electronsource). The acceleration voltage display portion of a control panel ona screen is clicked, and a [Flushing] button is pressed to open aflushing execution dialog. After it has been confirmed that a flushingintensity is 2, the flushing is executed. It is confirmed that anemission current by the flushing is from 20 A to 40 A. A sample holderhaving fixed thereto the toner particle is inserted into the samplechamber of the housing of the S-4800. [Origin] on the control panel ispressed to move the sample holder to an observation position.

The acceleration voltage display portion is clicked to open a HV settingdialog, and an acceleration voltage and the emission current are set to[2.0 kV] and [10 μA], respectively. In the [Basic] tab of an operationpanel, signal selection is placed in [SE], and the mode of a SE detectoris set to “Mix.”

Similarly, in the [Basic] tab of the operation panel, the probe current,focus mode, and WD of an electron optical system condition block are setto [Normal], [UHR], and [3.0 mm], respectively. The [ON] button of theacceleration voltage display portion of the control panel is pressed toapply the acceleration voltage.

<Observation of Condensation Product of Organosilicon Compound>

The mapping of the condensation product of the organosilicon compound isperformed as described below. First, the toner is sufficiently dispersedin a normal temperature-curable epoxy resin, and then the resultant iscured under an atmosphere at 40° C. for 2 days. A flaky sample having athickness of 40 nm is cut out of the resultant cured product with amicrotome including a diamond blade. After that, a sectional layer ofone particle of the toner is observed with a transmission electronmicroscope (TEM, apparatus name: JEM-2800, manufactured by JEOL Ltd.) atan enlargement magnification of from 10,000 to 100,000. Here, siliconatom mapping is performed by utilizing energy-dispersive X-rayspectroscopy (EDX). In the present invention, a place where a siliconatom was present was defined as a place where the condensation productof the organosilicon compound was present.

It was confirmed from the resultant silicon mapping image of the TEMimage of the particle of the toner that the layer of the condensationproduct of the organosilicon compound was formed on the surface of eachof the protrusions. In addition, it was confirmed that the ratio atwhich the toner base particle and each of the resin fine particles werein direct contact with each other at an interface therebetween withoutthrough the layer of the condensation product of the organosiliconcompound was 20% or more when the length of the interface was defined as100%. An example in which the toner base particle and the resin fineparticles are observed is illustrated in FIG. 2 (a whitely mappedportion represents the layer of the condensation product of theorganosilicon compound). In FIG. 2, the organosilicon compound is notobserved at the interface of the surface of each of the resin fineparticles on a side embedded in the toner base particle, and hence theratio at which the toner base particle and the resin fine particle arein direct contact with each other at the interface therebetween issubstantially 100% of the length of the interface.

<Calculation of Ratio h/A of Toner Particles>

The ratio h/A of the toner particle is calculated as described below. Asectional layer of the toner particle is observed by the above-mentionedmethod. At this time, the height h of an arbitrary protrusion and theclose-contact width A of the protrusion are measured, and the ratio h/Aof each fine particle is calculated. The ratios h/A are calculated for atotal of 100 protrusions, and the average of the calculated values isdefined as the ratio h/A of the toner particle.

In the present invention, the protrusions derived from the resin fineparticles are formed by bringing the resin fine particles into closecontact with the surface layer of the toner base particle, and are eachcovered with the condensation product of the organosilicon compound.Thus, there can be provided a toner that achieves both hightransferability and the prevention of member contamination at the timeof multi-sheet printing.

The present invention is specifically described below by way ofExamples. However, the present invention is not limited to theseExamples. All of “part(s)” of materials in Examples and ComparativeExamples are by mass, unless otherwise stated.

<Production of Aqueous Dispersion of Resin Fine Particles 1>

The following materials were dissolved in 42.0 parts ofN,N-dimethylformamide, and the solution was stirred for 1 hour whilenitrogen bubbling was performed. After that, the solution was heated to110° C. to produce a mixed solution.

Styrene 59.5 parts  n-Butyl acrylate 7.7 parts Methacrylic acid 2.8parts

A mixed solution of 2.1 parts of tert-butyl peroxy isopropylmonocarbonate (product name: PERBUTYL I, manufactured by Nippon Oil &Fats Co., Ltd.) serving as an initiator and 37.0 parts of toluene wasdropped into the mixed solution. The resultant mixed liquid was held at110° C. for 4 hours. After that, the resultant reaction product wascooled and dropped into 1,000.0 parts of methanol. Thus, a precipitatewas obtained. The resultant precipitate was dissolved in 120.0 parts oftetrahydrofuran, and then the solution was dropped into 1,800.0 parts ofmethanol to precipitate a white precipitate. The resultant whiteprecipitate was filtered, and was dried under reduced pressure at 90° C.to provide a resin 1.

200.0 Parts of methyl ethyl ketone was loaded into a reaction vesselincluding a stirring machine, a condenser, a temperature gauge, and anitrogen-introducing tube, and 100.0 parts of the resin 1 was added tothe methyl ethyl ketone to be dissolved therein. Next, 28.5 parts of a1.0 mol/L aqueous solution of potassium hydroxide was slowly added tothe solution, and the mixture was stirred for 10 minutes. After that,500.0 parts of ion-exchanged water was slowly dropped into the mixtureto be emulsified therein.

The resultant emulsified product was distilled under reduced pressure tobe desolvated, and ion-exchanged water was added to adjust the resinconcentration of the desolvated product to 10%. Thus, an aqueousdispersion of resin fine particles 1 was obtained.

<Production of Aqueous Dispersions of Resin Fine Particles 2 to 11>

Aqueous dispersions of resin fine particles 2 to 11 were each producedunder the same conditions as those of the aqueous dispersion of theresin fine particles 1 except that the amounts of various reagents werechanged as shown in Table 1.

TABLE 1 MMA/ MAA/ 4-VSA/ KOH/ St/parts BA/parts parts parts parts partsResin fine 59.5 7.7 0.0 2.8 0.0 28.5 particles 1 Resin fine 63.3 4.9 0.00.0 5.6 28.5 particles 2 Resin fine 59.5 7.7 0.0 2.8 0.0 52.4 particles3 Resin fine 59.5 7.7 0.0 2.8 0.0 47.6 particles 4 Resin fine 59.5 7.70.0 2.8 0.0 43.8 particles 5 Resin fine 59.5 7.7 0.0 2.8 0.0 37.9particles 6 Resin fine 59.5 7.7 0.0 2.8 0.0 23.7 particles 7 Resin fine59.5 7.7 0.0 2.8 0.0 18.4 particles 8 Resin fine 59.5 7.7 0.0 2.8 0.012.3 particles 9 Resin fine 67.2 0.0 0.0 0.0 5.6 28.5 particles 10 Resinfine 0.0 0.0 67.2 0.0 5.6 28.5 particles 11

In Table 1, St represents styrene, BA represents n-butyl acrylate, MMArepresents methyl methacrylate, MAA represents methacrylic acid, 4-VSArepresents 4-vinylsalicylic acid, and KOH represents the 1.0 mol/Laqueous solution of potassium hydroxide.

<Production of Aqueous Dispersion of Resin Fine Particles 12>

A temperature in a reaction vessel containing 100.0 parts of 2-butanoneand 50.0 parts of methanol was set to 60° C. while nitrogen bubbling wasperformed. After that, the following mixed solutions were simultaneouslydropped from different vessels into the reaction vessel over 60 minutes.

2-Acrylamido-2-methylpropanesulfonic acid mixed solution2-Acrylamido-2-methylpropanesulfonic acid  9.0 parts Styrene 79.3 partsn-Butyl acrylate 10.3 parts 2-Butanone 100.0 parts  Methanol 50.0 partsDimethyl-2,2′-azobis(2-methyl propionate)  1.0 part4-Vinylpyridine-containing mixed solution 4-Vinylpyridine  1.9 parts2-Butanone 50.0 parts

After the dropping, the mixture was stirred at 60° C. for 8 hours, andwas cooled to room temperature to provide a polymer-containingcomposition. The resultant polymer-containing composition was droppedinto 1,400.0 parts of methanol to provide a precipitate. The resultantprecipitate was washed with 200 parts of methanol twice, and was thendried under reduced pressure at 90° C. to provide a resin 12.

200 Parts of methyl ethyl ketone was loaded into a reaction vesselincluding a stirring machine, a condenser, a temperature gauge, and anitrogen-introducing tube, and 100.0 parts of the resin 12 was added tothe methyl ethyl ketone to be dissolved therein. Then, 28.5 parts of a1.0 mol/L aqueous solution of potassium hydroxide was slowly added tothe solution, and the mixture was stirred for 10 minutes. After that,500.0 parts of ion-exchanged water was slowly dropped into the mixtureto provide an emulsified product.

The resultant emulsified product was distilled under reduced pressure tobe desolvated, and ion-exchanged water was added to adjust the resinconcentration of the desolvated product to 10%. Thus, an aqueousdispersion of resin fine particles 12 was obtained.

<Production of Aqueous Dispersion of Resin Fine Particles 13>

An aqueous dispersion of resin fine particles 13 was obtained under thesame conditions as those of the aqueous dispersion of the resin fineparticles 12 except that the composition of the2-acrylamido-2-methylpropanesulfonic acid mixed solution and theaddition amount of the 1.0 mol/L aqueous solution of potassium hydroxidewere changed as described below.

2-Acrylamido-2-methylpropanesulfonic acid mixed solution:2-Acrylamido-2-methylpropanesulfonic acid  4.7 parts Styrene 83.1 partsn-Butyl acrylate 10.8 parts 2-Butanone 100.0 parts  Methanol 50.0 partsDimethyl-2,2′-azobis(2-methyl propionate)  1.0 part 1.0 mol/L aqueoussolution of potassium hydroxide 14.2 parts

<Production of Aqueous Dispersion of Resin Fine Particles 14>

The following materials were weighed in a reaction vessel including astirring machine, a condenser, a temperature gauge, and anitrogen-introducing tube, and were mixed and dissolved.

Styrene 87.3 parts n-Butyl acrylate 11.3 parts Hexanediol acrylate  0.4part n-Lauryl mercaptan  3.2 parts

A 10% aqueous solution of NEOGEN RK (manufactured by DKS Co., Ltd.) wasadded to and dispersed in the solution.

Further, an aqueous solution obtained by dissolving 0.15 part ofpotassium persulfate in 10.0 parts of ion-exchanged water was added tothe resultant while the resultant was slowly stirred for 10 minutes.After the vessel had been purged with nitrogen, the mixture wassubjected to emulsion polymerization at a temperature of 70° C. for 6.0hours.

After the completion of the polymerization, the reaction liquid wascooled to room temperature, and ion-exchanged water was added to adjustits resin concentration to 10%. Thus, an aqueous dispersion of resinfine particles 14 was obtained.

<Production of Aqueous Dispersion of Resin Fine Particles 15>

The following materials were weighed in a reaction vessel including astirring machine, a condenser, a temperature gauge, and anitrogen-introducing tube, and were subjected to an esterificationreaction at 190° C.

Propylene oxide-modified bisphenol A (2 mol adduct) 20.0 parts Propyleneoxide-modified bisphenol A (3 mol adduct) 80.0 parts Terephthalic acid20.0 parts Isophthalic acid 20.0 parts Tetrabutoxytitanium  0.3 part

After that, the temperature was increased to 220° C. and a pressure inthe system was gradually reduced, followed by a polycondensationreaction at 150 Pa. Thus, a resin 15 was obtained.

500.0 Parts of ion-exchanged water was added to 200.0 parts of theresultant resin 15, and the mixture was heated to 95° C. and meltedunder a warm bath. After that, while the molten product was sufficientlystirred with a homogenizer (manufactured by IKA: ULTRA-TURRAX T50) at7,800 rpm, a 0.1 mol/L aqueous solution of sodium hydrogen carbonate wasadded to set its pH to 7.0. The pH was identified with a pH meter (D-74:manufactured by Horiba, Ltd.) mounted with an electrode (9615S-10D:manufactured by Horiba, Ltd.). Further, a mixed solution of 3 parts bymass of sodium dodecylbenzenesulfonate and 297.0 parts by mass ofion-exchanged water was gradually dropped into the mixture to beemulsified and dispersed therein. After that, ion-exchanged water wasadded to adjust the resin concentration of the resultant to 10%. Thus,an aqueous dispersion of resin fine particles 15 was obtained.

The following pH measurement was performed with the pH meter and theelectrode described above.

<Production of Aqueous Dispersions of Resin Fine Particles 16 to 21>

Aqueous dispersions of resin fine particles 16 to 21 were each obtainedunder the same conditions as those in the production of the aqueousdispersion of the resin fine particles 15 except that a polymerizationtime and the pressure were arbitrarily changed.

The number-average particle diameter, peak top molecular weight Mp, andglass transition temperature Tg of each of the resin fine particles 1 to21 produced as described above were measured. The results are summarizedin Table 2.

TABLE 2 Particle diameter/nm Tg/° C. Mp Resin fine particles 1 102 8215,142 Resin fine particles 2 103 89 15,039 Resin fine particles 3 11 8015,088 Resin fine particles 4 17 82 14,976 Resin fine particles 5 30 8115,085 Resin fine particles 6 52 80 15,011 Resin fine particles 7 208 8015,071 Resin fine particles 8 304 82 14,985 Resin fine particles 9 50780 15,099 Resin fine particles 10 98 98 15,015 Resin fine particles 11103 107 14,978 Resin fine particles 12 202 74 15,139 Resin fineparticles 13 204 75 15,045 Resin fine particles 14 198 74 15,057 Resinfine particles 15 99 70 14,976 Resin fine particles 16 101 42 1,978Resin fine particles 17 100 51 2,993 Resin fine particles 18 100 605,021 Resin fine particles 19 102 73 31,238 Resin fine particles 20 10182 50,819 Resin fine particles 21 100 91 81,983 Resin fine particles 2296 — — Resin fine particles 23 106 — —

<Production of Aqueous Dispersion of Resin Fine Particles 22>

A 10% aqueous solution of EPOSTAR MX (MX050W manufactured by NipponShokubai Co., Ltd.) was produced to provide an aqueous dispersion ofresin fine particles 22. The number-average particle diameter of theresin fine particles 22 is shown in Table 2, but a Tg evaluation couldnot be performed because the resin fine particles 22 showed no change inspecific heat in the range of from 30° C. to 200° C. In addition, asample solution for an Mp evaluation could not be produced becausesubstantially no dissolution of the resin fine particles 22 intetrahydrofuran occurred. Accordingly, an Mp evaluation could not beperformed. The molecular weight of each of the resin fine particles 22is considered to be 50,000 or more because the resin fine particles areeach a thermosetting resin.

<Production of Aqueous Dispersion of Resin Fine Particles 23>

A 10% aqueous solution of EPOSTAR MX (MX100W manufactured by NipponShokubai Co., Ltd.) was produced to provide an aqueous dispersion ofresin fine particles 23. The number-average particle diameter of theresin fine particles 23 is shown in Table 2, but a Tg evaluation couldnot be performed because the resin fine particles 23 showed no change inspecific heat in the range of from 30° C. to 200° C. In addition, asample solution for an Mp evaluation could not be produced becausesubstantially no dissolution of the resin fine particles 23 intetrahydrofuran occurred. Accordingly, an Mp evaluation could not beperformed. The molecular weight of each of the resin fine particles 23is considered to be 50,000 or more because the resin fine particles areeach a thermosetting resin.

<Preparation of Organosilicon Compound Liquid 1>

Ion-exchanged water 90.0 parts Methyltrimethoxysilane (silicon compound)10.0 parts

The above-mentioned materials were mixed, and diluted hydrochloric acidwas added to adjust the pH of the mixture to 4.0. After that, theresultant was stirred for 1 hour while being heated to 60° C. in a waterbath. Thus, an organosilicon compound liquid 1 was prepared.

<Preparation of Organosilicon Compound Liquids 2 to 10>

Organosilicon compound liquids 2 to 10 were each prepared in the samemanner as in the preparation of the organosilicon compound liquid 1except that the kind of the organosilicon compound was changed as shownin Table 3.

TABLE 3 Organosilicon compound Organosilicon compound liquid 1Methyltrimethoxysilane Organosilicon compound liquid 2Methyltriethoxysilane Organosilicon compound liquid 3Ethyltrimethoxysilane Organosilicon compound liquid 4Vinyltrimethoxysilane Organosilicon compound liquid 5Vinyltriethoxysilane Organosilicon compound liquid 6Propyltrimethoxysilane Organosilicon compound liquid 7Methacryloxypropyltrimethoxysilane Organosilicon compound liquid 8Hexyltrimethoxysilane Organosilicon compound liquid 9Octadecyltrimethoxysilane Organosilicon compound liquid 10Dimethyldimethoxysilane

<Method of Producing Toner Base Particle-dispersed Liquid 1>

14.0 Parts of sodium phosphate (dodecahydrate) (manufactured by RasaIndustries, Ltd.) was loaded into 390.0 parts of ion-exchanged water ina reaction vessel, and the temperature of the mixture was held at 65° C.for 1.0 hour while the reaction vessel was purged with nitrogen.

While the mixture was stirred with T.K. Homomixer (manufactured byTokushu Kika Kogyo Co., Ltd.) at 12,000 rpm, an aqueous solution ofcalcium chloride obtained by dissolving 9.2 parts of calcium chloride(dihydrate) in 10.0 parts of ion-exchanged water was collectively loadedinto the reaction vessel. Thus, an aqueous medium containing adispersion stabilizer was prepared. Further, diluted hydrochloric acidwas loaded into the aqueous medium in the reaction vessel to adjust itspH to 6.0. Thus, an aqueous medium 1 was prepared.

(Preparation of Polymerizable Monomer Composition)

Styrene 60.0 parts C.I. Pigment Blue 15:3  6.5 parts

The above-mentioned materials were loaded into an attritor (manufacturedby Nippon Coke & Engineering Co., Ltd.), and were dispersed withzirconia particles each having a diameter of 1.7 mm at 220 rpm for 5.0hours to prepare a pigment-dispersed liquid. Next, the followingmaterials were added to the pigment-dispersed liquid.

Styrene 10.0 parts n-Butyl acrylate 30.0 parts Polyester resin(terephthalic acid-propylene  5.0 parts oxide-modified bisphenol Acopolymer) Fischer-Tropsch wax (melting point: 70° C.)  7.0 parts

The temperature of the above-mentioned materials was kept at 65° C., andthe materials were uniformly dissolved and dispersed with T.K. Homomixerat 500 rpm. Thus, a polymerizable monomer composition was prepared.

(Granulation Step)

While the temperature of the aqueous medium 1 was kept at 70° C. and thenumber of revolutions of a high-speed stirring apparatus was kept at12,000 rpm, the polymerizable monomer composition was loaded into theaqueous medium 1, and 9.0 parts of t-butyl peroxypivalate serving as apolymerization initiator was added to the mixture. The resultant wasgranulated as it was with the stirring apparatus for 10 minutes whilethe number of revolutions was maintained at 12,000 rpm.

(Polymerization Step)

The stirring machine was changed from the high-speed stirring apparatusto a propeller stirring blade, and the granulated product was held at70° C. and polymerized for 5.0 hours while being stirred at 150 rpm. Apolymerization reaction was performed by increasing the temperature to85° C. and heating the resultant at the temperature for 2.0 hours.Ion-exchanged water was added to adjust the concentration of toner baseparticles in the resultant dispersion liquid to 20.0 mass %. Thus, atoner base particle-dispersed liquid 1 was obtained. The number-averageparticle diameter (D1) of the toner base particles 1 was 5.9 μm, and theweight-average particle diameter (D4) thereof was 6.5 μm.

<Method of Producing Toner Base Particle-dispersed Liquid 2>

The following materials were mixed in a reaction tank including acooling tube, a stirring machine, and a nitrogen-introducing tube.

Terephthalic acid 29.0 partsPolyoxypropylene(2.2)-2,2-bis(4-hydroxyphenyl)propane 80.0 partsTitanium dihydroxybis(triethanol aminate)  0.1 part

After that, the mixture was heated to 200° C., and was subjected to areaction for 9 hours while nitrogen was introduced into the tank andwater to be produced was removed. Further, 5.8 parts of trimelliticanhydride was added to the resultant, and the mixture was heated to 170°C. and subjected to a reaction for 3 hours to synthesize a polyesterresin.

Next, the following materials were loaded into an autoclave, and thesystem was purged with nitrogen. After that, while the mixture wasincreased in temperature and stirred, its temperature was held at 180°C.

Low-density polyethylene (melting point: 100° C.) 20.0 parts Styrene64.0 parts n-Butyl acrylate 13.5 parts Acrylonitrile  2.5 parts

Subsequently, 50.0 parts of a 2.0 mass % solution of t-butylhydroperoxide in xylene was continuously dropped into the system for 4.5hours, and the resultant mixture was cooled. After that, the solvent wasseparated and removed. Thus, a graft polymer in which a styrene-acryliccopolymer was grafted to the polyethylene was obtained.

The following materials were sufficiently mixed with Mitsui HenschelMixer (manufactured by Mitsui Miike Chemical Engineering Machinery Co.,Ltd.), and then the mixture was melted and kneaded with a biaxialkneader (manufactured by Ikegai Iron Works, Ltd.) whose temperature hadbeen set to 100° C.

Polyester resin 100.0 parts  Fischer-Tropsch wax (melting point: 70° C.)5.0 parts Graft polymer 5.0 parts C.I. Pigment Blue 15:3 5.0 parts

The resultant kneaded product was cooled and coarsely pulverized to 1 mmor less with a hammer mill to provide a coarsely pulverized product.Next, the resultant coarsely pulverized product was finely pulverizedwith Turbo Mill manufactured by Turbo Kogyo Co., Ltd. to provide afinely pulverized product having a size of about 5 μm. After that, fineand coarse powders were further cut with a multi-division classifierutilizing a Coanda effect. Thus, toner base particles 2 were obtained.The toner base particles 2 had a number-average particle diameter (D1)of 5.6 μm and a weight-average particle diameter (D4) of 6.5 μm.

14.0 Parts of sodium phosphate (dodecahydrate) (manufactured by RasaIndustries, Ltd.) was loaded into 390.0 parts of ion-exchanged water ina reaction vessel, and the temperature of the mixture was held at 65° C.for 1.0 hour while the vessel was purged with nitrogen.

While the mixture was stirred with T.K. Homomixer at 12,000 rpm, anaqueous solution of calcium chloride obtained by dissolving 9.2 parts ofcalcium chloride (dihydrate) in 10.0 parts of ion-exchanged water wascollectively loaded into the reaction vessel. Thus, an aqueous mediumcontaining a dispersion stabilizer was prepared. Further, dilutedhydrochloric acid was loaded into the aqueous medium in the reactionvessel to adjust its pH to 6.0. Thus, an aqueous medium was prepared.

200.0 Parts of the toner base particles were loaded into the aqueousmedium, and were dispersed therein at a temperature of 60° C. for 15minutes while being rotated with T.K. Homomixer at 5,000 rpm.Ion-exchanged water was added to adjust the concentration of the tonerbase particles in the resultant dispersion liquid to 20.0 mass %. Thus,a toner base particle-dispersed liquid 2 was obtained.

<Method of Producing Toner Base Particle-dispersed Liquid 3>

The following materials were weighed, and were mixed and dissolved.

Styrene 82.6 parts  n-Butyl acrylate 9.2 parts Acrylic acid 1.3 partsHexanediol acrylate 0.4 part  n-Lauryl mercaptan 3.2 parts

A 10% aqueous solution of NEOGEN RK (manufactured by DKS Co., Ltd.) wasadded to and dispersed in the solution. Further, while the resultant wasslowly stirred for 10 minutes, an aqueous solution obtained bydissolving 0.15 part of potassium persulfate in 10.0 parts ofion-exchanged water was added thereto. After purging with nitrogen, themixture was subjected to emulsion polymerization at a temperature of 70°C. for 6.0 hours. After the completion of the polymerization, thereaction liquid was cooled to room temperature, and ion-exchanged waterwas added thereto. Thus, a resin particle-dispersed liquid having asolid content concentration of 12.5% and a number-average particlediameter of 0.2 μm was obtained.

The following materials were weighed and mixed.

Ester wax (melting point: 70° C.) 100.0 parts NEOGEN RK  15.0 partsIon-exchanged water 385.0 parts

The mixture was dispersed with a wet jet mill JN100 (manufactured byJokoh Co., Ltd.) for 1 hour to provide a wax-dispersed liquid. The solidcontent concentration of the wax particle-dispersed liquid was 20.0%.

The following materials were weighed and mixed.

C.I. Pigment Blue 15:3 100.0 parts NEOGEN RK  15.0 parts Ion-exchangedwater 885.0 parts

The mixture was dispersed with a wet jet mill JN100 for 1 hour toprovide a colorant-dispersed liquid. The solid content concentration ofthe colorant-dispersed liquid was 10.0%.

Resin particle-dispersed liquid 160.0 parts Wax-dispersed liquid  10.0parts Colorant-dispersed liquid  10.0 parts Magnesium sulfate  0.2 part

The above-mentioned materials were dispersed with a homogenizer(manufactured by IKA), and then the resultant was warmed to 65° C. whilebeing stirred. The resultant was stirred at 65° C. for 1.0 hour, and wasthen observed with an optical microscope. As a result, it was confirmedthat aggregate particles having a number-average particle diameter of6.0 μm were formed. 2.2 Parts of NEOGEN RK (manufactured by DKS Co.,Ltd.) was added to the resultant, and then the temperature of themixture was increased to 80° C., followed by stirring for 2.0 hours.Thus, a fused toner particle precursor was obtained.

The mixture containing the toner base particles was cooled and thenfiltered. A solid separated by the filtration was washed with 720.0parts of ion-exchanged water under stirring for 1.0 hour. The dispersionliquid containing the toner particle precursor was filtered and dried toprovide toner base particles 3. The number-average particle diameter(D1) of the toner base particles 3 was 6.2 μm, and the weight-averageparticle diameter (D4) thereof was 7.1 μm.

14.0 Parts of sodium phosphate (dodecahydrate) (manufactured by RasaIndustries, Ltd.) was loaded into 390.0 parts of ion-exchanged water ina vessel, and the temperature of the mixture was held at 65° C. for 1.0hour while the vessel was purged with nitrogen.

While the mixture was stirred with T.K. Homomixer at 12,000 rpm, anaqueous solution of calcium chloride obtained by dissolving 9.2 parts ofcalcium chloride (dihydrate) in 10.0 parts of ion-exchanged water wascollectively loaded into the mixture. Thus, an aqueous medium containinga dispersion stabilizer was prepared. Further, diluted hydrochloric acidwas loaded into the aqueous medium to adjust its pH to 6.0. Thus, anaqueous medium was prepared.

100.0 Parts of the toner base particles 3 were loaded into the aqueousmedium, and were dispersed at a temperature of 60° C. for 15 minuteswhile being rotated with T.K. Homomixer at 5,000 rpm. Ion-exchangedwater was added to adjust the solid content concentration of the tonerbase particles 3 in the resultant dispersion liquid to 20.0%. Thus, atoner base particle-dispersed liquid 3 was obtained.

<Method of Producing Toner Base Particle-dispersed Liquid 4>

660.0 Parts of ion-exchanged water and 25.0 parts of a 48.5% aqueoussolution of sodium dodecyl diphenyl ether disulfonate were mixed andstirred, and the mixture was stirred with T.K. Homomixer at 10,000 rpmto prepare an aqueous medium.

The following materials were loaded into 500.0 parts of ethyl acetate,and were dissolved with a propeller-type stirring apparatus at 100 rpmto prepare a dissolved liquid.

Styrene/butyl acrylate copolymer (copolymerization 100.0 parts  ratio:80/20) Polyester resin 3.0 parts (terephthalic acid-propyleneoxide-modified bisphenol A copolymer) C.I. Pigment Blue 15:3 6.5 partsFischer-Tropsch wax (melting point: 70° C.) 9.0 parts

Next, 150.0 parts of the aqueous medium was loaded into a vessel, andwas stirred with T.K. Homomixer at a number of revolutions of 12,000rpm. 100.0 Parts of the dissolved liquid was added to the aqueousmedium, and the contents were mixed for 10 minutes to prepare anemulsified slurry.

After that, 100.0 parts of the emulsified slurry was loaded into a flaskhaving set therein a tube for degassing, a stirring machine, and atemperature gauge. While being stirred at a stirring peripheral speed of20 m/min, the slurry was desolvated at 30° C. for 12 hours under reducedpressure, and was aged at 45° C. for 4 hours to provide a desolvatedslurry. After the desolvated slurry had been filtered under reducedpressure, 300.0 parts of ion-exchanged water was added to the resultantfilter cake, and the contents were mixed and redispersed with T.K.Homomixer (at a number of revolutions of 12,000 rpm for 10 minutes),followed by filtration.

The resultant filter cake was dried with a dryer at 45° C. for 48 hours,and was sieved with a mesh having an aperture of 75 μm to provide tonerbase particles 4. The number-average particle diameter (D1) of the tonerbase particles 4 was 5.7 μm, and the weight-average particle diameter(D4) thereof was 6.9 μm.

14.0 Parts of sodium phosphate (dodecahydrate) (manufactured by RasaIndustries, Ltd.) was loaded into 390.0 parts of ion-exchanged water ina vessel, and the temperature of the mixture was held at 65° C. for 1.0hour while the vessel was purged with nitrogen.

While the mixture was stirred with T.K. Homomixer at 12,000 rpm, anaqueous solution of calcium chloride obtained by dissolving 9.2 parts ofcalcium chloride (dihydrate) in 10.0 parts of ion-exchanged water wascollectively loaded into the mixture. Thus, an aqueous medium containinga dispersion stabilizer was prepared. Further, diluted hydrochloric acidwas loaded into the aqueous medium to adjust its pH to 6.0. Thus, anaqueous medium was prepared.

100.0 Parts of the toner base particles 4 were loaded into the aqueousmedium, and were dispersed at a temperature of 60° C. for 15 minuteswhile being rotated with T.K. Homomixer at 5,000 rpm. Ion-exchangedwater was added to adjust the solid content concentration of the tonerbase particles 4 in the resultant dispersion liquid to 20.0%. Thus, atoner base particle-dispersed liquid 4 was obtained.

<Method of Producing Toner 1>

The following samples were weighed in a reaction vessel, and were mixedwith a propeller stirring blade.

Resin fine particle-dispersed liquid 1  20.0 parts Toner baseparticle-dispersed liquid 1 500.0 parts

Next, diluted hydrochloric acid was added to adjust the pH of the mixedsolution to 5.5. After the temperature of the mixed solution had beenset to 70° C., the mixed solution was held for 1 hour while beingstirred with a propeller stirring blade.

After that, 60.0 parts of the organosilicon compound liquid 1 was addedto the mixed solution, and the pH of the whole was adjusted to 9.0 witha 1.0 mol/L aqueous solution of NaOH. Further, the resultant was heldfor 4 hours while being stirred, followed by air-cooling to atemperature of 25° C.

Diluted hydrochloric acid was added to the resultant mixed solution toadjust its pH to 1.5, and then the whole was stirred for 2 hours,followed by filtration, water washing, and drying. Thus, toner particles1 having protrusions derived from the resin fine particles on theirsurfaces were obtained. The toner particles were defined as a toner 1.

<Methods of Producing Toners 2 and 4 to 32>

Toners 2 and 4 to 32 were each obtained in the same manner as in themethod of producing the toner 1 except that the kinds and amounts of theorganosilicon compound liquid and the resin fine particle-dispersedliquid, and the kind of the toner base particle-dispersed liquid werechanged as shown in Table 4.

<Method of Producing Toner 3>

Toner particles 3 were obtained by changing the kinds and amounts of theorganosilicon compound liquid and the resin fine particle-dispersedliquid, and the kind of the toner base particle-dispersed liquid asshown in Table 4. 0.5 Part of silica particles having a number-averageparticle diameter of 50 nm, which had been treated withhexamethyldisilazane, were added to the toner particles 3, and themixture was stirred with a fluidized bed mixer (Mitsui Henschel Mixer,manufactured by Mitsui Miike Chemical Engineering Machinery Co., Ltd.)for 5 minutes to provide a toner 3.

<State of Close Contact of Resin Fine Particles with Toner BaseParticle>

Sections of each one particle of toners was observed with a transmissionelectron microscope, and a portion where a toner base particle and resinfine particles were in contact with each other was observed. Then, ineach of the toner particles 1 to 32, it was confirmed from the siliconmapping image of the TEM image of each one particle of the toner thatthe layer of the condensation product of the organosilicon compound wasformed on the surface of each of the protrusions, and that the ratio atwhich the toner base particle and each of the resin fine particles werein direct contact with each other at an interface therebetween withoutthrough the layer of the condensation product of the organosiliconcompound was 20% or more.

Subsequently, the ratios h/A of the toner particles were calculated bythe above-mentioned method. The results are shown in Table 4. In each ofthe toner particles 1 to 32, the ratio h/A fell within the range of from0.2 to 1.5, and hence the resin fine particles were in direct contactwith the toner base particle.

TABLE 4 Organosilicon compound liquid Fine particle-dispersed liquidToner base Kind Parts Kind Parts particle-dispersed liquid h/A Toner 1Organosilicon 60.0 Resin fine 20.0 Toner base 0.52 compound liquid 1particle-dispersed liquid 1 particle-dispersed liquid 1 Toner 2Organosilicon 60.0 Resin fine 20.0 Toner base 0.57 compound liquid 2particle-dispersed liquid 1 particle-dispersed liquid 1 Toner 3Organosilicon 60.0 Resin fine 20.0 Toner base 0.50 compound liquid 2particle-dispersed liquid 1 particle-dispersed liquid 1 Toner 4Organosilicon 50.0 Resin fine 20.0 Toner base 0.49 compound liquid 2particle-dispersed liquid 1 particle-dispersed liquid 2 Toner 5Organosilicon 70.0 Resin fine 20.0 Toner base 0.55 compound liquid 2particle-dispersed liquid 1 particle-dispersed liquid 3 Toner 6Organosilicon 80.0 Resin fine 20.0 Toner base 0.49 compound liquid 2particle-dispersed liquid 1 particle-dispersed liquid 4 Toner 7Organosilicon 60.0 Resin fine 20.0 Toner base 0.53 compound liquid 3particle-dispersed liquid 1 particle-dispersed liquid 1 Toner 8Organosilicon 60.0 Resin fine 20.0 Toner base 0.47 compound liquid 4particle-dispersed liquid 12 particle-dispersed liquid 1 Toner 9Organosilicon 30.0 Resin fine 20.0 Toner base 0.45 compound liquid 5particle-dispersed liquid 15 particle-dispersed liquid 1 Organosilicon30.0 compound liquid 10 Toner 10 Organosilicon 60.0 Resin fine 20.0Toner base 0.61 compound liquid 6 particle-dispersed liquid 2particle-dispersed liquid 1 Toner 11 Organosilicon 60.0 Resin fine 20.0Toner base 0.52 compound liquid 7 particle-dispersed liquid 1particle-dispersed liquid 1 Toner 12 Organosilicon 60.0 Resin fine 20.0Toner base 0.51 compound liquid 8 particle-dispersed liquid 1particle-dispersed liquid 1 Toner 13 Organosilicon 60.0 Resin fine 20.0Toner base 0.49 compound liquid 9 particle-dispersed liquid 1particle-dispersed liquid 1 Toner 14 Organosilicon 60.0 Resin fine 2.0Toner base 0.31 compound liquid 3 particle-dispersed liquid 3particle-dispersed liquid 1 Toner 15 Organosilicon 60.0 Resin fine 3.0Toner base 0.36 compound liquid 3 particle-dispersed liquid 4particle-dispersed liquid 1 Toner 16 Organosilicon 60.0 Resin fine 6.0Toner base 0.43 compound liquid 3 particle-dispersed liquid 5particle-dispersed liquid 1 Toner 17 Organosilicon 60.0 Resin fine 10.0Toner base 0.45 compound liquid 3 particle-dispersed liquid 6particle-dispersed liquid 1 Toner 18 Organosilicon 60.0 Resin fine 40.0Toner base 0.89 compound liquid 3 particle-dispersed liquid 7particle-dispersed liquid 1 Toner 19 Organosilicon 60.0 Resin fine 60.0Toner base 1.08 compound liquid 3 particle-dispersed liquid 8particle-dispersed liquid 1 Toner 20 Organosilicon 60.0 Resin fine 100.0Toner base 1.27 compound liquid 3 particle-dispersed liquid 9particle-dispersed liquid 1 Toner 21 Organosilicon 60.0 Resin fine 20.0Toner base 0.48 compound liquid 4 particle-dispersed liquid 13particle-dispersed liquid 1 Toner 22 Organosilicon 60.0 Resin fine 20.0Toner base 0.55 compound liquid 4 particle-dispersed liquid 14particle-dispersed liquid 1 Toner 23 Organosilicon 60.0 Resin fine 20.0Toner base 0.24 compound liquid 5 particle-dispersed liquid 16particle-dispersed liquid 1 Toner 24 Organosilicon 60.0 Resin fine 20.0Toner base 0.35 compound liquid 5 particle-dispersed liquid 17particle-dispersed liquid 1 Toner 25 Organosilicon 60.0 Resin fine 20.0Toner base 0.41 compound liquid 5 particle-dispersed liquid 18particle-dispersed liquid 1 Toner 26 Organosilicon 60.0 Resin fine 20.0Toner base 0.56 compound liquid 5 particle-dispersed liquid 19particle-dispersed liquid 1 Toner 27 Organosilicon 60.0 Resin fine 20.0Toner base 0.54 compound liquid 5 particle-dispersed liquid 20particle-dispersed liquid 1 Toner 28 Organosilicon 60.0 Resin fine 20.0Toner base 0.70 compound liquid 5 particle-dispersed liquid 21particle-dispersed liquid 1 Toner 29 Organosilicon 60.0 Resin fine 20.0Toner base 0.67 compound liquid 6 particle-dispersed liquid 10particle-dispersed liquid 1 Toner 30 Organosilicon 60.0 Resin fine 20.0Toner base 0.74 compound liquid 6 particle-dispersed liquid 11particle-dispersed liquid 1 Toner 31 Organosilicon 60.0 Resin fine 20.0Toner base 0.71 compound liquid 6 particle-dispersed liquid 22particle-dispersed liquid 1 Toner 32 Organosilicon 60.0 Resin fine 20.0Toner base 0.69 compound liquid 6 particle-dispersed liquid 23particle-dispersed liquid 1

<Method of Producing Comparative Toner 1>

The following samples were weighed in a reaction vessel, and were mixedwith a propeller stirring blade.

Resin fine particle-dispersed liquid 1  20.0 parts Toner baseparticle-dispersed liquid 1 500.0 parts

Next, diluted hydrochloric acid was added to adjust the pH of the mixedsolution to 5.5. After the temperature of the mixed solution had beenset to 70° C., the mixed solution was held for 1 hour while beingstirred with a propeller stirring blade. After that, the pH of the wholewas adjusted to 9.0 with a 1.0 mol/L aqueous solution of NaOH. Further,the resultant was held for 4 hours while being stirred, followed byair-cooling to a temperature of 25° C.

Diluted hydrochloric acid was added to the resultant mixed solution toadjust its pH to 1.5, and then the whole was stirred for 2 hours,followed by filtration, water washing, and drying. Thus, comparativetoner particles 1 having protrusions derived from the resin fineparticles on their surfaces were obtained. 2.0 Parts of silica particleshaving a number-average particle diameter of 100 nm, which had beentreated with hexamethyldisilazane, were added to the comparative tonerparticles 1, and the mixture was stirred with a fluidized bed mixer(Mitsui Henschel Mixer, manufactured by Mitsui Miike ChemicalEngineering Machinery Co., Ltd.) for 5 minutes to provide a comparativetoner 1. In the comparative toner 1, the surface of each of theprotrusions derived from the resin fine particles was not covered withthe condensate of an organosilicon compound.

<Method of Producing Comparative Toner 2>

The following samples were weighed in a reaction vessel, and were mixedwith a propeller stirring blade.

Resin fine particle-dispersed liquid 1  20.0 parts Toner baseparticle-dispersed liquid 1 500.0 parts

Next, diluted hydrochloric acid was added to adjust the pH of the mixedsolution to 4.0. After the temperature of the mixed solution had beenset to 70° C., the mixed solution was held for 1 hour while beingstirred with a propeller stirring blade. After that, 2.0 parts of anaqueous solution of the initial polymer of hexamethylolmelamine (solidcontent concentration: 80%) was added to the mixed solution, and thewhole was stirred for 1 hour. After that, the pH of the resultant wasadjusted to 7.0 with a 1.0 mol/L aqueous solution of NaOH. Further, theresultant was held for 4 hours while being stirred, followed byair-cooling to a temperature of 25° C.

Diluted hydrochloric acid was added to the resultant mixed solution toadjust its pH to 1.5, and then the whole was stirred for 2 hours,followed by filtration, water washing, and drying. Thus, comparativetoner particles 2 having protrusions derived from the resin fineparticles on their surfaces were obtained. 2.0 Parts of silica particleshaving a number-average particle diameter of 100 nm, which had beentreated with hexamethyldisilazane, were added to the comparative tonerparticles 2, and the mixture was stirred with a fluidized bed mixer(Mitsui Henschel Mixer, manufactured by Mitsui Miike ChemicalEngineering Machinery Co., Ltd.) for 5 minutes to provide a comparativetoner 2. In the comparative toner 2, the surface of each of theprotrusions derived from the resin fine particles was not covered withthe condensate of an organosilicon compound.

<Method of Producing Comparative Toner 3>

The following samples were weighed in a reaction vessel, and were mixedwith a propeller stirring blade.

Resin fine particle-dispersed liquid 3 20.0 parts Organosilicon compoundliquid 5 60.0 parts Toner base particle-dispersed liquid 1 500.0 parts 

Next, diluted hydrochloric acid was added to adjust the pH of the mixedsolution to 5.5. After the temperature of the mixed solution had beenset to 70° C., the mixed solution was held for 1 hour while beingstirred with a propeller stirring blade. After that, the pH of the wholewas adjusted to 9.0 with a 1.0 mol/L aqueous solution of NaOH. Further,the resultant was held for 4 hours while being stirred, followed byair-cooling to a temperature of 25° C.

Diluted hydrochloric acid was added to the resultant mixed solution toadjust its pH to 1.5, and then the whole was stirred for 2 hours,followed by filtration, water washing, and drying. Thus, comparativetoner particles 3 having protrusions derived from the resin fineparticles on their surfaces were obtained. The comparative tonerparticles were defined as a comparative toner 3. In the comparativetoner 3, the layer of the condensate of the organosilicon compound waspresent between each of the resin fine particles and the toner baseparticle, and hence the resin fine particles were not in direct contactwith the toner base particle.

<Method of Producing Comparative Toner 4>

500.0 g of the toner base particle-dispersed liquid 1 was weighed in areaction vessel, and was stirred with a propeller stirring blade.

Next, diluted hydrochloric acid was added to adjust the pH of the mixedsolution to 5.5. After the temperature of the mixed solution had beenset to 70° C., the mixed solution was held for 1 hour while beingstirred with a propeller stirring blade. After that, 60.0 parts of theorganosilicon compound liquid 7 was added to the mixed solution, and thepH of the whole was adjusted to 9.0 with a 1.0 mol/L aqueous solution ofNaOH. Further, the resultant was held for 4 hours while being stirred,followed by air-cooling to a temperature of 25° C.

Diluted hydrochloric acid was added to the resultant mixed solution toadjust its pH to 1.5, and then the whole was stirred for 2 hours,followed by filtration, water washing, and drying. Thus, comparativetoner particles 4 were obtained. The comparative toner particles weredefined as a comparative toner 4. In the comparative toner 4,protrusions derived from resin fine particles were not present.

[Evaluations of Examples 1 to 32 and Comparative Examples 1 to 4]

The evaluations of Examples 1 to 32 and Comparative Examples 1 to 4 wereperformed by using the toners 1 to 32 and the comparative toners 1 to 4,respectively.

First, a color laser printer (LBP-712Ci, manufactured by Canon Inc.)reconstructed so as to have a process speed of 300 mm/sec was used, andthe toner of its cyan cartridge was removed. 120 g of each of the toners1 to 32 and the comparative toners 1 to 4 was loaded into the cartridge.After that, the following evaluations were performed.

<Member Contamination Evaluation>

The cartridge was mounted on the cyan station of the printer, and achart having a printing ratio of 5% was output on 1 sheet of A4 sizeplain paper Office 70 (manufactured by Canon Marketing Japan Inc., 70g/m²) under normal temperature and normal humidity (temperature: 23° C.,humidity: 60% RH). After that, the image was output on 2 sheets of thepaper, and the apparatus was stopped for 10 seconds. The foregoingoperation was repeated, and every time the image was output on 1,000sheets of the paper while the cartridge was replenished with the toner,the tops of a developing blade and a developing roller were visuallyobserved, and the presence or absence of the occurrence of resin fusionwas confirmed. Member contamination was evaluated by the followingcriteria through the use of the endurance number of sheets on which theresin fusion occurred as an indicator. The results are shown in Table 5.

A: No resin fusion occurs in each of the developing blade and thedeveloping roller by the time when the image is output on 16,000 sheets.

B: The resin fusion occurs in the developing blade or the developingroller by the time when the image is output on 16,000 sheets.

C: The resin fusion occurs in the developing blade or the developingroller by the time when the image is output on 10,000 sheets.

D: The resin fusion occurs in the developing blade or the developingroller by the time when the image is output on 5,000 sheets.

<Transferability Evaluation>

The cartridge was mounted on the cyan station of the printer, and achart having a printing ratio of 1% was output on 1 sheet of A4 sizeplain paper Office 70 (manufactured by Canon Marketing Japan Inc., 70g/m²) under normal temperature and normal humidity (temperature: 23° C.,humidity: 60% RH), followed by the output of a solid image. Theapparatus was stopped at the time of the transfer of the toner from aphotosensitive member to an intermediate transfer member, and a tonerlaid-on level M1 (mg/cm²) on the photosensitive member before thetransfer step and a toner laid-on level M2 (mg/cm²) on thephotosensitive member after the transfer step were measured. Thetransfer efficiency of the toner was calculated from the followingequation by using the measured toner laid-on levels, and was defined asinitial transfer efficiency.

Further, the chart having a printing ratio of 1% was continuously outputon 16,000 sheets of the paper while the cartridge was replenished withthe toner. After that, the transfer efficiency of the toner wascalculated and defined as transfer efficiency after endurance. Theresults are shown in Table 5.Transfer efficiency (%)=(M1−M2)/M1×100

The transferability of the toner was evaluated by the followingevaluation criteria.

A: The transfer efficiency is 95% or more.

B: The transfer efficiency is 90% or more and less than 95%.

C: The transfer efficiency is 85% or more and less than 90%.

D: The transfer efficiency is less than 85%.

<Low-temperature Fixability>

The cartridge was mounted on the cyan station of the printer, and asolid image (toner laid-on level: 0.9 mg/cm²) was output on A4 sizeplain paper Office 70 (manufactured by Canon Marketing Japan Inc., 70g/m²) under normal temperature and normal humidity (temperature: 23° C.,humidity: 60% RH). The image was fixed while a fixation temperature waschanged, and then the low-temperature fixability of the toner wasevaluated. The A4 size plain paper Office 70 (manufactured by CanonMarketing Japan Inc., 70 g/m²) was used as the paper. The results areshown in Table 5.

A: No offset occurs at 150° C.

B: An offset occurs at 150° C.

C: An offset occurs at 160° C.

D: An offset occurs at 170° C.

<Charge Rising Performance>

The process cartridge was mounted on the cyan station of the printer,and was left at rest in a low-temperature and low-humidity environment(15° C./10% RH, hereinafter referred to as “L/L environment”) for 48hours together with A4 size plain paper Office 70 (manufactured by CanonMarketing Japan Inc., 70 g/m²).

In the L/L environment, an image having the following portions wasoutput on the paper: a horizontal belt-like solid black image portion(laid-on level: 0.45 mg/cm²) having a length of 10 mm, the portionranging from a position distant from the leading end of the paper by 10mm to a position distant therefrom by 20 mm when the paper wasvertically viewed; a solid white image portion (laid-on level: 0.00mg/cm²) having a length of 10 mm in a downstream direction from thesolid black image portion; and a halftone image portion (laid-on level:0.20 mg/cm²) having a length of 100 mm in a further downstream directionfrom the solid white image position. The charge rising performance ofthe toner was evaluated by the following criteria based on a differencebetween the image density of a portion on the halftone image portionpositioned downstream from the solid black image portion by one round ofthe developing roller and the image density of a portion thereonpositioned downstream from the solid white image portion by one round ofthe developing roller. The measurement of each of the image densitieswas performed by measuring a density relative to an image in a whiteground portion having an image density of 0.00 with Macbeth ReflectionDensitometer RD918 (manufactured by Macbeth) mounted with an amberfilter in accordance with an attached instruction manual. The resultantrelative density was defined as a value for the image density.

When the charge rising performance is satisfactory, the toner suppliedonto a charging roller is rapidly charged. Accordingly, the imagedensity after the solid black image portion and that after the solidwhite image portion do not differ from each other, and hence asatisfactory image is obtained.

(Evaluation Criteria for Charge Rising Performance)

A: The image density difference is less than 0.03, and hence the chargerising performance is extremely excellent.

B: The image density difference is 0.03 or more and less than 0.06, andhence the charge rising performance is excellent.

C: The image density difference is 0.06 or more and less than 0.10.

D: The image density difference is 0.10 or more.

TABLE 5 Initial Transfer Member transfer efficiency after Charge risingToner contamination efficiency/% endurance/% Fixability performanceExample 1 Toner 1 A A 98 A 97 A A 0.01 Example 2 Toner 2 A A 99 A 97 A A0.01 Example 3 Toner 3 A A 98 A 96 A A 0.01 Example 4 Toner 4 A A 98 A96 A A 0.01 Example 5 Toner 5 A A 98 A 97 A A 0.01 Example 6 Toner 6 A A98 A 96 A A 0.02 Example 7 Toner 7 A A 99 A 97 A A 0.02 Example 8 Toner8 A A 99 A 97 A A 0.02 Example 9 Toner 9 A B 94 B 92 A B 0.04 Example 10Toner 10 A A 97 A 95 A A 0.02 Example 11 Toner 11 B A 98 A 95 A A 0.01Example 12 Toner 12 B A 96 B 93 A B 0.05 Example 13 Toner 13 C B 94 C 88A C 0.08 Example 14 Toner 14 B B 93 B 91 A C 0.09 Example 15 Toner 15 AA 97 A 95 A B 0.03 Example 16 Toner 16 A A 98 A 96 A A 0.02 Example 17Toner 17 A A 99 A 97 A A 0.01 Example 18 Toner 18 A A 99 A 98 A A 0.01Example 19 Toner 19 B A 98 A 96 A A 0.01 Example 20 Toner 20 C A 99 B 94A A 0.02 Example 21 Toner 21 A A 98 A 95 A B 0.05 Example 22 Toner 22 BA 97 B 94 A C 0.08 Example 23 Toner 23 C B 93 C 86 A B 0.03 Example 24Toner 24 B A 95 B 92 A A 0.02 Example 25 Toner 25 A A 97 A 96 A A 0.01Example 26 Toner 26 A A 99 A 97 A A 0.01 Example 27 Toner 27 A A 98 A 96A A 0.01 Example 28 Toner 28 B A 96 B 94 A A 0.01 Example 29 Toner 29 BA 97 B 92 B A 0.01 Example 30 Toner 30 C A 98 C 89 C A 0.01 Example 31Toner 31 C A 98 C 87 C C 0.07 Example 32 Toner 32 C A 99 C 85 C C 0.06Comparative Comparative D A 97 D 84 B C 0.07 Example 1 toner 1Comparative Comparative C A 99 C 87 D B 0.05 Example 2 toner 2Comparative Comparative D A 99 B 93 A A 0.01 Example 3 toner 3Comparative Comparative B C 89 C 86 A D 0.12 Example 4 toner 4

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions.

This application claims the benefit of Japanese Patent Application No.2017-96223, filed May 15, 2017, and Japanese Patent Application No.2017-193187, filed Oct. 3, 2017, which are hereby incorporated byreference herein in their entirety.

What is claimed is:
 1. A toner comprising a toner particle, said tonerparticle comprising: a toner base particle containing a binder resin anda colorant; resin fine particles; and a condensation product of anorganosilicon compound represented by formula (1)(R^(a))_(n)—Si—(R^(b))_(4-n)  (1) where R^(a) independently represents ahalogen atom, a hydroxy group, or an alkoxy group, R^(b) independentlyrepresents an alkyl group, an alkenyl group, an acetoxy group, an acylgroup, an aryl group, an acryloxyalkyl group, or a methacryloxyalkylgroup, and n represents an integer of from 2 to 4, wherein said tonerparticle has protrusions on a surface thereof, said protrusions beingformed from said resin fine particles which are in direct contact withsaid toner base particle, and the surfaces of said protrusions beingcovered with said condensation product.
 2. A toner according to claim 1,wherein n represents 2 or
 3. 3. A toner according to claim 1, whereinthe resin fine particle has a number-average particle diameter of 10 to500 nm.
 4. A toner according to claim 1, wherein the resin fine particlecontains a thermoplastic resin.
 5. A toner according to claim 1, whereinthe resin fine particle has a glass transition temperature Tg of 40 to110° C.
 6. A toner according to claim 1, wherein the resin fine particlecontains a resin comprising an ionic functional group.